Caltha palustris is a species of wet habitats, often
in bogs or in shallow water and sometimes in canopy openings
in swamps. The inflorescence is easily recognizeable as
a member of the Arum Family (Araceae) that includes Symplocarpus
foetidus (skunk cabbage), Arisaema triphyllum
(jack-in-the-pulpit) and Acorus americanus (sweet
flag). The broad white structure is called the spathe and
the nearly cylindrical collection of flowers is called the
spadix. Flowers of the spadix produce bright red berries
later in the year and sometimes remain on the plant into
winter.

Calla palustris is a northern species ranging from
Alaska across canada and extending south to Minnesota and
Wisconsin (and barely enters Illinois in the northeastern-most
county), east to Pennsylvania and New Jersey . In Wisconsin
it is found mostly north of the tension zone, with the majority
of known locations in the northern half of the state.